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Biomedical subjects

P Newman

Publications and source records attributed to P Newman.

At least 19 recordsLinked to original sources

Randomized controlled trial to investigate influence of the fluid challenge on duration of hospital stay and perioperative morbidity in patients with hip fractures.

BACKGROUND: A prospective, randomized controlled trial comparing conventional intraoperative fluid management with two differing methods of invasive haemodynamic monitoring to optimize intraoperative fluid therapy, in patients undergoing proximal femoral fracture repair under general anaesthesia. METHODS: Ninety patients randomized to three groups; conventional intraoperative fluid management (Gp CON, n=29), and two groups receiving additional repeated colloid fluid challenges guided by central venous pressure (Gp CVP, n=31) or oesophageal Doppler ultrasonography (Gp DOP, n=30). Primary outcome measures were time to medical fitness to discharge, hospital stay and postoperative morbidity. RESULTS: The fluid challenge resulted in significantly greater perioperative changes in central venous pressure between Gp CVP and Gp CON (mean 5 (95% confidence interval 3-7) mm Hg) (P<0.0001). Important perioperative changes were also shown in Gp DOP with increases of 49.4 ms (19.7-79.1 ms) in the corrected flow time, 13.5 ml (7.4-19.6 ml) in stroke volume, and 0.9 (0.49-1.39) litre min(-1) in cardiac output. As a result, fewer patients in Gp CVP and Gp DOP experienced severe intraoperative hypotension (Gp CON 28% (8/29), Gp CVP 9% (3/31), Gp DOP 7% (2/30), P=0.048 (chi-squared, 2 degrees of freedom (df). No differences were seen between the three groups when major morbidity and mortality were combined, P=0.24 (chi-squared, 2 df). Postoperative recovery for survivors, as defined by time to be deemed medically fit for discharge, was significantly faster, in comparison with Gp CON, in both the Gp CVP (10 vs 14 (95% confidence interval 8-12 vs 12-17) days, P=0.008 (t-test)), and Gp DOP (8 vs 14 (95% confidence interval 6-12 vs 12-17) days, P=0.023 (t-test). There were no significant differences between groups, for survivors, with respect to acute orthopaedic hospital and total hospital stay. CONCLUSIONS: Invasive intraoperative haemodynamic monitoring with fluid challenges during repair of femoral fracture under general anaesthetic shortens time to being medically fit for discharge.

Aged↗

Sustainable urban water systems in rich and poor cities--steps towards a new approach.

The 'big pipes in, big pipes out' approach to urban water management was developed in the 19th century for a particular linear urban form. Large, sprawling car-dependent cities are pushing this approach to new limits in rich cities and it has never worked in poor cities. An alternative which uses new small-scale technology and is more community-based, is suggested for both rich and poor countries. The Sydney Olympics and a demonstration project in Java show that the approach can work.

Conservation of Natural Resources↗

PECAM-1 (CD31) expression modulates bleeding time in vivo.

PECAM-1 is a 130-kd member of the Ig superfamily present on endothelial cells, platelets, polymorphonuclear leukocytes, monocytes, and lymphocytes. Its expression begins early in development and persists through adulthood. PECAM-1 functions as an adhesion and signaling molecule between adjacent endothelial cells and between endothelial cells and circulating blood elements. Antibodies directed against PECAM-1 have been shown to affect angiogenesis, endothelial cell migration, and polymorphonuclear leukocyte transmigration. Furthermore, its dimerization is associated with the modulation of integrin affinity. Antibody inhibition studies suggest that PECAM-1 plays a role in modulating thrombosis; however, recent in vitro aggregation studies performed on platelets harvested from PECAM-1-deficient mice revealed no abnormalities. In this report we demonstrate prolonged in vivo bleeding times in PECAM-1-deficient mice. This abnormality was not corrected when wild-type hematopoietic precursors were engrafted into marrow-ablated PECAM-1-deficient mice. Furthermore, normal bleeding times were observed when marrow-ablated wild-type mice were engrafted with hematopoietic precursors harvested from PECAM-1-deficient mice. These studies are consistent with a role for PECAM-1 in modulating thrombosis in the vasculature, which is potentially mediated by endothelial cell PECAM-1 expression.

Animals↗

Are triglyceride breast implants really biocompatible?

A case of augmentation mammaplasty with triglyceride implants is presented. Histological examination of the capsules 3 years postimplantation showed retained, irregular, refractile yellow-brown fragments embedded in granulomatous tissue.

Adult↗

Is centralized histopathology review necessary for screen-detected breast lesions?

To address quality requirements for breast pathology in the Australian screening programme, one breast cancer Screening and Assessment Service initiated a process of central pathologic review of all lesions detected through the service. The aim of this study was to measure concordance between the initial and review pathology, and to assess the merit of routine review. Concordance was measured by observed agreement and the kappa statistic for 267 women with 273 lesions. Concordance was excellent for the four classification schemes examined, good for the identification of benign lesions and hyperplasia, and excellent for the identification of DCIS or invasive carcinoma. For the sub-categorization of hyperplasias and invasive carcinomas concordance was good, but was poor for the sub-typing of DCIS. Initial and review concordance was acceptable, suggesting that disagreement among pathologists may not present a major impediment to the provision of dependable diagnoses. Full case review is unnecessary for benign lesions or invasive carcinoma, but should be maintained for DCIS and hyperplasias.

Journal Article↗

Blockade of platelet endothelial cell adhesion molecule-1 (PECAM-1) protects against ischemia-reperfusion injury in muscle flaps at microcirculatory level.

Several lines of evidence show that platelet endothelial cell adhesion molecule-1 (PECAM-1), a component of endothelial cell junctions, is required for leukocyte transmigration through endothelial cell monolayers. Polymorphonuclear leukocytes play an important role in ischemia-reperfusion injury. We sought to determine whether administering an anti-PECAM-1 antibody would prevent or attenuate ischemia-reperfusion injury in a rat cremaster muscle flap injury model. Eighteen male Sprague-Dawley rats were divided into three groups. Group I (control): Cremaster muscle island flaps were dissected for baseline measurements of eight indicators: numbers of rolling, sticking, and transmigrating neutrophils, numbers of rolling and sticking lymphocytes, number of perfused capillaries, endothelial edema, and vessel permeability. Group II: The prepared cremaster flap was subjected to 4 hours of ischemia and 24 hours of reperfusion. Group III: The muscle flap was subjected to ischemia and reperfusion as in group II, and anti-PECAM-1 antibodies (1 mg/kg) were injected subcutaneously 15 minutes before reperfusion. Blood vessels were observed in vivo under an intravital microscopy system. Microvascular permeability was made visible with injected fluorescein isothiocyanate-labeled albumin and evaluated with Kontron Elektronik computer software. The ischemia-reperfusion-alone group (group II) presented a 225-percent increase in the activation of sticking leukocytes (2.4 +/- 0.4 to 7.8 +/- 0.8, p < 0.05) (p < 0.01). This leukocyte activation was reduced by 83 percent following anti-PECAM-1 monoclonal antibody treatment (1.3 +/- 0.5 per 100 microm) (p < 0.01). At 24 hours, endothelial injury in group II was confirmed by a 4-fold increase in the number of transmigrating leukocytes into the interstitial space (7.6 +/- 1.2 per field versus 1.9 +/- 0.4 per field in controls). This phenomenon was reduced by 85 percent following anti-PECAM-1 monoclonal antibody treatment (1.1 +/- 0.2 per field) (p < 0.01). Analysis showed that the number of flowing capillaries was 67 percent lower in group II (6.8 +/- 0.3 to 2.2 +/- 0.7, p < 0.01). Anti-PECAM-1 antibody treatment caused a 2.5-fold increase in this number (5.6 +/- 0.5, p < 0.01). Microcirculatory permeability index showed a 180-percent increase in group II (p < 0.05) when compared with baseline values. This increased albumin leakage was effectively attenuated by antibody treatment (p < 0.05). Blocking the action of PECAM-1 in vivo by administering monoclonal antibodies significantly attenuated ischemia-reperfusion injury, presumably by inhibiting transendothelial migration of neutrophils and by increasing capillary perfusion at a muscle flap microcirculatory level.

Animals↗

Ceruminous gland neoplasia.

Ceruminous glands are modified sweat glands, confined to the skin lining of the cartilaginous part of the external auditory meatus. Tumours arising from these glands are extremely rare. Confusion exists regarding the nomenclature 'ceruminoma' and controversies prevail on the standard way of management. Treatment often involves a multidisciplinary approach, requiring reconstruction after extensive surgical resection. A case report of adenoid cystic carcinoma of ceruminous glands is presented along with discussion of the various pathological types and a review of management.

Adult↗

Epithelioid hemangioendothelioma presenting in the skin: a clinicopathologic study of eight cases.

Epithelioid hemangioendothelioma arising in the skin is extremely rare, and the majority of documented cases have developed in association with an underlying bone tumor. We report eight patients with an age range of 29-84 years (mean 53), who presented with primary cutaneous tumors at a variety of sites including the palm, shin, neck, knee, nose, back, and penis with a duration of between 6 and 12 months. Histologically, all eight cases presented as circumscribed nodules with an overlying acanthotic epidermis, three showing striking acrosyringeal proliferation, reminiscent of eccrine syringofibroadenoma. The tumors were composed of an admixture of slightly pleomorphic spindle and epithelioid cells with abundant, sharply defined eosinophilic cytoplasm and vesicular nuclei containing single nucleoli. Mitoses were generally sparse. All tumors showed intracytoplasmic lumina and intraluminal erythrocytes were occasionally apparent. The tumor cells were embedded in a myxoid or hyaline matrix. In contrast to visceral lesions, a vascular origin was not evident in any of our cases. The tumor cells variably expressed CD31, CD34, factor VIII-Rag, and smooth-muscle actin but not pankeratin or epithelial membrane antigen. Follow-up ranged from 4 months to 3 years. None of the lesions has thus far recurred and there have been no metastases.

Adult↗